Abstract: A sensor assembly, a force detection device and method, and construction machinery, the sensor assembly comprising a connecting part used for connecting a base to be tested and a bearing part used for bearing, the bearing part being connected to the connecting part, the bearing part comprising at least two sensing units with different measuring ranges, and the at least two sensing units being arranged to have a different initial gap (b1, b2) from the connecting part, so that corresponding initial gap (b1, b2) are eliminated when a load applied to the bearing part reaches different extents. The different initial gaps (b1, b2) are eliminated by means of the load reaching a different extent, so that the sensing units with different measuring ranges can provide detection feedback in the respective working conditions in which the units have the highest measurement precision and thereby ensure the accuracy of detection results.